Is this true/correct? Read it on a different forum.

[fartoblue]

I do struggle with this. I can see it makes sense but it goes against everything else I have read ie: Static water level, Nute ec going up means you are feeding to high as the plants can't take any more nutrients so don't drink, reduce ec and plants will drink more then work your way up from there.


This is what was posted is it correct??

Most people assume that with a rising EC, it is the plants way of saying, I don't want more food, here, have some back.

What is actually happening is this.

Plants roots take in water/nutrients through a process called Osmosis. Effectively, if you think in terms of the roots having their own internal EC.
The osmosis process will always try to balance out the EC's, taking from the higher side of the barrier and giving to the lower part.

So if the EC of the nutrient solution is higher than the "internal EC", then food & water will flow from the solution to the roots, this is the normal process.
"If however, the EC of the solution is lower than the "internal EC", then the balancing will work the other way and nutrition will be leeched from the roots to the solution. "
A res change or increase in EC should resolve depending on the other factors such as ph and water levels.

 

[Logan Burke]

Yes that is correct, you get this adverse reaction where a falling PH and rising ppm could mean that you're feeding too strong, or it could mean that the ppm's aren't high enough and that nutrients are actually flowing out from the roots into the res's water. If you're in a situation where you don't know which is the case, you may have to try lowering ppm's and seeing if it resolves the problem. If it doesn't, and especially if it gets worse, then you know that you need to raise your ec a nice bit. That property is what can make hydroponics tricky.

 

[rkymtnman]

If however, the EC of the solution is lower than the "internal EC", then the balancing will work the other way and nutrition will be leeched from the roots to the solution. "
A res change or increase in EC should resolve depending on the other factors such as ph and water levels

 

[Logan Burke]

Yeah that chart has helped me narrow down my course of action a few times in DWC now. I'd actually had an issue recently where my ph and ppm's were both falling on a daily basis. On a hunch, I raised the ppm's a considerable about (from 150 to about 300-350) and the problem totally resolved. Has never happened to me before, but at least now I know what to do if it happens again.

 

[fartoblue]

Yes that is correct, you get this adverse reaction where a falling PH and rising ppm could mean that you're feeding too strong, or it could mean that the ppm's aren't high enough and that nutrients are actually flowing out from the roots into the res's water. If you're in a situation where you don't know which is the case, you may have to try lowering ppm's and seeing if it resolves the problem. If it doesn't, and especially if it gets worse, then you know that you need to raise your ec a nice bit. That property is what can make hydroponics tricky.

Logan mate now I am totally bamboozled. So am I right in thinking it is really a case of looking at your plants to see what they are telling you then adjusting your EC/ppm accordingly, sort of old school growing and just using the ec truncheon as a rough guide.

 

[rkymtnman]

here's my priority list for rdwc:

1. pH
2. pH
3. pH
4. water level dropping daily
5. EC dropping slightly daily

and not to be funny but pH out of whack will throw off everything else. and you'll be chasing your tail in a circle.

 

[Logan Burke]

here's my priority list for rdwc:

1. pH
2. pH
3. pH
4. water level dropping daily
5. EC dropping slightly daily

and not to be funny but pH out of whack will throw off everything else. and you'll be chasing your tail in a circle.

100% agree there!

Logan mate now I am totally bamboozled. So am I right in thinking it is really a case of looking at your plants to see what they are telling you then adjusting your EC/ppm accordingly, sort of old school growing and just using the ec truncheon as a rough guide.

Yes that is exactly how I felt myself when I encountered this issue, I had just thought that I was beginning to totally understand it haha. I personally feel like (maybe just for me at least) it comes down to a combination of watching the plant itself, and monitoring the numbers on your meters. I can typically find a symmetry where the numbers I'm getting from the root zone reflect the health and growth of the plant that I can see with my own two eyes. I try to combine concrete data (I record PH and PPM, nutes and water added every day) and my own reading of my plants to equal a course of action and where to go next.

 

[rkymtnman]

I personally feel like (maybe just for me at least) it comes down to a combination of watching the plant itself, and monitoring the numbers on your meters.

yep!
that's the thing with rdwc fartoblue, problems can arise very, very quickly. but the good news is that you can fix problems very quickly too.
it's very labor intensive compared to other grow methods but the results are worth the effort.

 

[fartoblue]

100% agree there!

Yes that is exactly how I felt myself when I encountered this issue, I had just thought that I was beginning to totally understand it haha. I personally feel like (maybe just for me at least) it comes down to a combination of watching the plant itself, and monitoring the numbers on your meters. I can typically find a symmetry where the numbers I'm getting from the root zone reflect the health and growth of the plant that I can see with my own two eyes. I try to combine concrete data (I record PH and PPM, nutes and water added every day) and my own reading of my plants to equal a course of action and where to go next.

yep!
that's the thing with rdwc fartoblue, problems can arise very, very quickly. but the good news is that you can fix problems very quickly too.
it's very labor intensive compared to other grow methods but the results are worth the effort.

Many thanks for taking the time to help me lads.
My first RDWC grow may have been a write off but I have learned so much that it has almost been worth it (almost). RDWC is more labour intensive which was something I did not expect but I would never go back to coco.
I have only been growing for 2 years and hadn't grown so much as a bunch of cress before then, so learning every day.

 

[Renfro]

here's my priority list for rdwc:

1. pH
2. pH
3. pH
4. water level dropping daily
5. EC dropping slightly daily

and not to be funny but pH out of whack will throw off everything else. and you'll be chasing your tail in a circle.

Yes and there is nothing like a pH dosing pump with RDWC. Total peace of mind (unless the probe goes bad and it does a run away dose lol)

 

[fartoblue]

Yes and there is nothing like a pH dosing pump with RDWC. Total peace of mind (unless the probe goes bad and it does a run away dose lol)

Now they do sound interesting I can get one called Milwaukee for 300 euro.

 

[Renfro]

Now they do sound interesting I can get one called Milwaukee for 300 euro.

I havent used the milwaukee, the blue labs are nice, agrotek makes a really nice setup but more than most will need at home.

 

[fartoblue]

Milwaukee Instruments pH Controller with Dosing Pump Kit Model MC720
The small and precise flow of the MP810 provides fully automated pH control of aqueous solutions in the hydroponic systems. It has been specifically designed to control the pH in mixing tanks for fertilization. The peristaltic pump allows you to maintain the ideal pH values in your tank. After selecting the desired pH setting from 5.5 to 9.5 pH, the pH controller measures the pH value of the solution and automatically adds pH adjustment (acid or alkaline) to change the liquid's pH to the desired selected level.

 

[fartoblue]

When I first decided to go RDWC I had visions of filling the tank and going on holiday for a week. PH fluctuations soon threw a spanner in the works of that idea, now this piece of kit gives me some hope.
Thanks for the info Renfro, I didn't know such a device existed.

 

[Renfro]

You really want a reliable one, if it goes wrong like a bad probe and over doses it can really mess things up. So see if you can find reviews on whatever unit you are looking at.

 

[Renfro]

Some models have a limit to prevent a massive overdose.

 

[fartoblue]

Blue lab a bit pricey at £380.00

Managing your pH just got easy!


This clever little kit both monitors and adjusts pH levels for you.


It’s completely plant safe, with a dosing lockout feature to prevent over-dosing. If there’s a power loss, your system will automatically continue dosing once it’s been restarted.


It’s easy to use with an on-screen guide. Simply set it up and forget about it, knowing the pH is taken care of.


• Complete 14 piece kit
• Automatically monitors and fine tunes pH
• Hands-free monitoring
• Plant-safe, green back lit LCD with adjustable brightness
• Large, easy to read displays
• Temperature compensation feature for accurate reading
• Easy to navigate, program and adjust
• Simple push button pH calibration
• On-screen guide
• Flashing high/low alarm with control lockouts
• Dosing lockouts to protect from over-dosing
• Automatically continues dosing on restart if there’s a power loss
• Water resistant
• Designed for wall mounting
• International power supply
• 4 metre acid/alkali resistant dosing tube included
• Replaceable double junction pH probe
• Separate temperature probe
• Replaceable peristaltic pump and tubes
• Suitable for system pH with reservoirs up to 760 Litres
• Use with undiluted pH adjuster

 

[ANC]

I'm getting used to Hydro now. I just don't take shit too seriously.
If the plants look good, I stick to emptying the res 2 twice a week, and yes, my res gets bigger as the growth progress.
I might do a pH check 2 days in and just bring it down where it should be. Mine always climbs a little, as I tend to underfeed slightly.

 

[rkymtnman]

When I first decided to go RDWC I had visions of filling the tank and going on holiday for a week.

just to tease you a bit,

i do drain to waste auto-feed GH waterfarms. i've been away 2 weeks (a fortnight for you mate) with no problems.

 

[fartoblue]

just to tease you a bit,

i do drain to waste auto-feed GH waterfarms. i've been away 2 weeks (a fortnight for you mate) with no problems.

Well, I was walking to work today in the rain dreaming of blue skies and sandy beaches whilst my automatic Ph adjuster takes care of everything while I am away. I then got to thinking about this gadget's practicality for long term use.

Whilst I do think these machines are a fantastic idea for short breaks, I am not to sure they would be ideal for long term continuous use. Going back to old school growing and not relying to much on technology if I have a dramatic Ph drop/increase I want to know about it as it is telling me I have a problem somewhere and I need to do something about it. The Ph controller would just mask the problem ( a bit like when you go to the doctors and they give you a bag full of pills). Maybe for a seasoned, experienced hydro grower who really has his system dialed in they would be a great labour and time saving device, but for us lesser mortals they should only be used for short breaks of a few days to a week.

I do still have a Ph controller on my Christmas list but as I run a perpetual grow I will need at least two of these machines so my wife had better start saving now.